For present 3rd–person singular, verbs are formed by adding the affix –s for both
regular and irregular verbs. In the case of verbs ending with a sibilant consonant, the
suffix –es is added. Also, verbs that end with –y preceded by a consonant have the –y
changed to –i- and then the suffix –es is added.
To form the present participle, the suffix –ing is added to all verbs. However,
the spelling of the present participle varies slightly according to the specific
environment. When the verb ends with –e, that –e is deleted and when the verb ends
with a consonant preceded by a short vowel, that consonant must be doubled. A few
verbs ending with –ie will have the –ie changed to –y and a few others ending with –c
will have a –k added before the suffix –ing.